This proposal addresses the need identified by the NIMH for innovative computer interfaces that can continuously acquire, analyze and store neurophysiological data for research and clinical use. We will develop affordable data acquisition hardware and software that will permit parallel recording, display, and analysis of multichannel neural responses with a Pentium-based PC system. The focus is on systems for use with arrays of up to 100 intracortical electrodes for acute and chronic animal investigations. The hardware systems will: i) amplify 100 channels of neural data, ii) acquire and store the times of super-threshold action potential waveforms or the unit identifiers(Phase II). The software tools will: i) control data acquisition processes, ii) display multi-unit spike activity, and iii) display 3-D neural activity (two spatial and one time dimension). Data file structure will be suitable for importing into third party data analysis software. Systems will be validated with synthesized data and in physiological investigations of network representations of visual stimuli in feline Vl, and drug effects on spontaneous activity and connectivities of neurons in feline sensory cortex. PROPOSED COMMERCIAL APPLICATION: The affordable data acquisition system will enable neuroscience researchers to use multielectrode arrays in 'slice' work and chronically implanted in the nervous systems of primates, felines, and rodent models to investigate the parallel processing and connectivities associated with normal or aberrant mental function. The system can also be used to develop therapeutic drugs; and to study the underlying mechanism both of the effect of drugs of abuse on the nervous system, and of the acquisition and loss of memory.